Control device for electric currents



Jan. 23, 1934. H. SELL 1,944,721

CONTROL DEVICE FOR ELECTRIC GUkRENTS Filed Sept. 4, 1930 unmlli' J121792. 4 figs Patented Jan.

examples of the In the accompanying drawing a invention are shown. Fig.1 1s a diagrammatic view of a device em- FFICE CONTROL DEVICE FORELECTRIC CURRENTS Helmut Sell, Berlin-Siemensstadt, German y,

& Halske, Aktiengesellschaft,- Siemensstadt, near Berlin,

Signor to Siemens ration of Germany Application September and Germany, acorpo- 4, 1930, Serial No. 479,642, in Germany February 15, 1930 5Claims. (01. 175-320) few working "17 there is connected,

resistances 14,15, 16 and for example at 12 and 13,

ment consisting of the a source of current.

If, however either th resistance either of the spirals 14 and 15 or ofthe spirals 16 coils 21 and 22 current the other.

Now if the screen be so attached an auxiliary hand 19 which facilitatesthe regulation to any desired normal position. This arrangement provesespecially advanta geous if it is built into a casing or cap in such amanner that said casing can be placed upon any desired measuringinstrument. For the generation of the air currents use can preierably bemade of a diaphragm by employing the sound-nozzleprinciple. In this casethe dia phragm is vibrated by means of electromagnets fed withalternating current of cycles for example.

An illustrative embodiment of a generator of an air stream is shown inFig. 4. This generator consists essentially of a housing 31, which has anozzle 7 located on the front thereoi. A diaphragm is provided in thecentral portion of said housing and is mounted in such a manner as to becapable of vibrating. Behind the diaphragm 30 electromagnets 32 of wellknown construction are provided. -By energizing the clectromagnets 32with an alternating current, or other periodically varying current, thediaphragm 30 vibrates in a well known manner. Due to the vibration orthe diaphragm 30, air streams with sharply defined cross-sections areejected from nozzle 7. In this manner, it is possible to produce streamsof air for impinging or flowing against the thermally sensitiveresistances.

The use of the invention is not, however by any means confined to thearrangements here described, which, of course, may be altered in theirdetails as may be required and are only intended to serve as anexplanation of the principle, as they can be extended to cover variouskinds of apparatus.

The broad possibility of application of the invention is in particulargiven by the fact that with the aid of vibrating diaphragms it isrendered possible in a simple manner to generate easily regulatableconstant air currents and although the generation of the air current isnot a material point still the use of the vibrating diaphragms for thispurpose is believed to be the most suitable.

The screen 9 moves edgewise between the nozzle 7 or the nozzles '7, 7and the resistances or temperature-sensitive members against which saidnozzles discharge air currents, and preferably the movement of thescreen is sub stantlally at right angles across the air current. In theconstructions illustrated, the screen 9 is curved, its center ofcurvature being on the axis about which the pivoted hand 8 swings. Bymoving the screen edgewise across the stream or current of air, I securevery accurate results,

. struck by said current, and

since the screen will then cut off the jet or current very sharply fromthe adjacent quiescent body of air, and the appliance will beexceedingly sensitive, in fact its degree of sensitiveness willcorrespond to the sensitiveness of, the instrument of which the hand 8forms part.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I de clarethat What I claim is:-

1. A device of the character described, comprising means for giving apredetermined direction to a current of fluid, a temperature -sen sitivemember arranged to be struck by said current, a screen movable edgewiseacross said current to prevent its reaching said member, and means formoving said screen.

2. A device of the character described, comprising means for giving apredetermined direction to a sharply defined jet of fluid, a termperature-sensitive member arranged to be struck by said jet. a screenmovable edgewise across said jet to intercept the same and prevent itfrom reaching the said member, and means for moving said screen.

3. A device of the character described, comprising means for giving apredetermined direction to a current of fluid, a temperature-sensitivemember arranged to be struck by said current, a screen movable edgewiseacross said current substantially at right angles to the direction ofsaid current, to prevent said current from reaching said member, and,means for moving said screen.

4. A' device of the character described, comprising means for giving apredetermined direction to a current of fluid, a temperature-sensitivemember permanently in the same position relatively to said means, andarranged to be struck by said current, a curved screen adapted tointercept said current, and means for eilecting a relative movement,about the center of curvature of said screen as an axis, between thescreen on one hand and the said member and means on the other hand.

5. A device of the character described, comprising a pivoted hand, meansfor giving a predetermined direction to a current of fluid. atemperature-sensitive member arranged to be said hand to move in unisontherewith and arranged to intercept said current of fluid, said screenhaving a curvature centered on the pivot of said hand, and being adaptedto move edgewise across said current.

HELMUT SELL.

a screen secured to

